A method for eliminating traffic congestion on fast roads based on connected autonomous driving technology

Abstract

The present invention discloses a method for eliminating traffic congestion on expressways based on networked autonomous driving technology. The method relates to the technical field of dissipating traffic congestion on expressways. When a traffic congestion is detected, the networked autonomous driving technology is applied to cause a designated vehicle upstream of the congested area to decelerate to a designated speed, maintaining a large distance between the designated vehicle and the congestion downstream. Subsequently, after the designated vehicle has traveled at the designated speed for a period of time, when it is a designated distance away from the vehicle in front of it, the designated vehicle is accelerated back to its pre-deceleration free flow speed. Accordingly, the following vehicles of the designated vehicle are adjusted based on changes in the driving behavior of the preceding vehicle. Ultimately, the dissipation wave generated by the acceleration of the designated vehicle meets the compression wave generated by the deceleration, completely eliminating the congestion. The present invention enhances the initiative, flexibility, precision, and efficiency of congestion elimination, resolving the problems of existing methods, which suffer from passive control, low precision, and unsatisfactory results.

Description

Technical Field

[0001] The present invention relates to the technical field of eliminating traffic congestion on expressways, and in particular to a method for eliminating traffic congestion on expressways based on networked autonomous driving technology. Background Art

[0002] Current research on eliminating traffic congestion on expressways, both domestically and internationally, primarily focuses on fixed bottleneck areas such as diverging and merging zones. These methods rely on fixed speed limit signs and traffic lights to control incoming traffic. These methods are passive, inaccurate, and ineffective. With the development of connected autonomous driving technology, real-time monitoring of traffic flow, extraction of vehicle trajectory data, real-time dissemination of information from the Internet of Vehicles, and high-precision autonomous driving have become increasingly feasible. Therefore, by actively regulating vehicle driving behavior and coordinating the flow of upstream and downstream traffic, connected autonomous driving technology can dynamically eliminate traffic congestion or fluctuations in real time. Summary of the Invention

[0003] In response to the above-mentioned deficiencies in the prior art, the present invention provides a method for eliminating traffic congestion on expressways based on networked autonomous driving technology, which solves the problems of passive control, low precision and unsatisfactory effects of the prior art methods.

[0004] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a method for eliminating traffic congestion on expressways based on connected autonomous driving technology, comprising the following steps:

[0005] S1: Based on the Internet of Vehicles technology, the cloud control platform is used to detect the vehicle traffic operation status in real time and obtain vehicle operation status data;

[0006] S2: Based on vehicle operating status data and connected autonomous driving technology, when a traffic congestion is detected downstream via a cloud-based control platform, designated vehicles upstream of the congestion area are decelerated to a specified speed in advance, ensuring that the designated vehicles maintain a specified distance from the congested vehicles downstream.

[0007] S3: When the upstream designated vehicle is at a specified distance from the preceding vehicle, the cloud control platform is used to control the designated vehicle to accelerate back to its free flow speed before deceleration.

[0008] S4: Based on the driving behavior of the designated vehicle, the driving behaviors of the vehicles following the designated vehicle are adjusted accordingly according to the changes of the preceding vehicle;

[0009] S5: Based on the adjustment results, when the compression wave formed by the deceleration of the specified vehicle meets the dissipation wave formed by the acceleration during the upstream transmission process, the traffic congestion is eliminated, the vehicle maintains a constant free flow speed, and the elimination of expressway traffic congestion based on connected autonomous driving technology is completed.

[0010] The beneficial effects of the above scheme are: applying the networked autonomous driving technology to slow down a designated vehicle upstream of the congested area to a designated speed, so that the designated vehicle maintains a large distance from the congestion downstream; then, after the designated vehicle has traveled at the designated speed for a period of time, when the designated vehicle is at a designated distance from the vehicle in front of it, the vehicle is accelerated to recover to the free flow speed before deceleration; accordingly, the vehicles following the designated vehicle are adjusted according to the changes in the driving behavior of the vehicle in front. Ultimately, the dissipation wave generated by the acceleration of the designated vehicle meets the compression wave generated by the deceleration, and the congestion is completely eliminated. Based on the networked autonomous driving technology, the present invention actively controls the driving behavior of individual vehicles, replacing the passive, wide-area method of implementing signal, speed, and flow control at a fixed position, thereby improving the initiative, flexibility, accuracy, and efficiency of congestion elimination, and solving the problems of passive control methods, low accuracy, and unsatisfactory effects of existing methods.

[0011] Furthermore, the deceleration time of the upstream designated vehicle in S2 is the time when the congestion is detected after it is fully formed, and the formula is:

[0012] t 减速 =t1

[0013] Among them, t 减速 is the deceleration moment of the leading vehicle in the upstream of the congestion, and t1 is the moment when the congestion is detected after it is fully formed.

[0014] The beneficial effect of the above further solution is that: through the above technical solution, the moment when congestion is fully formed and detected is used as the deceleration moment of the upstream designated vehicle.

[0015] Furthermore, the upstream designated vehicle in S2 decelerates to the designated speed in advance, and the formula is:

[0016]

[0017] Among them, v ai When the designated vehicle i is the deceleration head vehicle, its designated speed after deceleration is is the position where vehicle i-1 accelerates to leave the traffic jam after driving at the current free flow speed, d is the parking distance between adjacent vehicles, is the position of vehicle i at time t1, t i-1 The moment when vehicle i-1, traveling at the current free-flow speed, gets stuck in a traffic jam and then accelerates to leave.

[0018] The beneficial effect of the above further solution is that: through the above technical solution, the speed that the congested upstream vehicle can maintain after deceleration is obtained.

[0019] Furthermore, the expected headway for the upstream designated vehicle in S2 to decelerate to the designated speed in advance is:

[0020] hai =v ai *t e

[0021] Among them, h ai is the expected headway distance corresponding to the decelerated speed, t e is the driver's desired headway.

[0022] The beneficial effect of the above further solution is that: through the above technical solution, the headway between designated decelerated vehicles upstream in the congestion that accelerate to recover to the free flow speed is the expected headway between vehicles corresponding to the free flow speed.

[0023] Furthermore, the vehicle i specified in S2 satisfies the following conditions:

[0024]

[0025] Among them, Δt is the delay time of a single vehicle in congestion, When vehicle i is designated as the upstream leading vehicle to slow down in advance, the moment when the last decelerated vehicle returns to the free flow speed before deceleration is When vehicle i-1 is the leading vehicle in the upstream slowdown process, the moment when the last slowed vehicle returns to its free flow speed before deceleration. When vehicle i+1 is designated as the upstream leading vehicle to slow down in advance, the moment when the last decelerated vehicle returns to its pre-deceleration free flow speed;

[0026]

[0027] in, When vehicle i is designated as the deceleration head vehicle, it decelerates and then accelerates, T i is the time required for the dissipation wave generated by the acceleration of the designated vehicle i to catch up with the compression wave generated by its deceleration, l is the headway when the designated vehicle i returns to the free flow speed before deceleration, v f is the free flow speed of the vehicle, is the position where vehicle i accelerates, is the position where vehicle i decelerates, h1 is the headway between vehicles upstream in the congested area, and t 检测 is the time when the designated vehicle i decelerates, t0 is the time when the first vehicle in congestion starts to decelerate, x0 is the position where the first vehicle in congestion starts to decelerate, and x1 is the position where the first vehicle in congestion accelerates to return to free flow speed.

[0028] The beneficial effect of the above further scheme is: in order to eliminate traffic congestion as soon as possible, the leading vehicle in the upstream of the congestion that slows down in advance should allow the last vehicle participating in the deceleration to return to the free flow speed as soon as possible, that is, the moment when the compression wave caused by vehicle deceleration and acceleration meets the dissipation wave, which is also the moment when the congestion is completely eliminated.

[0029] Furthermore, the headway distance between vehicles when the vehicle accelerates and recovers to the free flow speed before deceleration is specified in S3 as:

[0030] l=v f *t e .

[0031] The beneficial effect of the above further solution is that: through the above technical solution, the headway between designated decelerated vehicles upstream in congestion that accelerate to recover to the free flow speed is the expected headway between vehicles corresponding to the free flow speed.

[0032] Furthermore, the time when the vehicle accelerates is specified in S3 as:

[0033]

[0034] The beneficial effect of the above further solution is: through the above technical solution, the moment when the leading vehicle of the upstream decelerating vehicle in the congestion accelerates is the moment when the distance between the leading vehicle and the previous vehicle (the last vehicle caught in the congestion) is 1 meter. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The present invention is a flow chart of a method for eliminating traffic congestion on expressways based on connected autonomous driving technology.

[0036] Figure 2 This is a system structure diagram of an example of the present invention.

[0037] Figure 3 It is an implementation effect diagram of the present invention. DETAILED DESCRIPTION

[0038] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0039] like Figure 1 As shown, a method for eliminating rapid road traffic congestion based on connected autonomous driving technology includes the following steps:

[0040] S1: Based on the Internet of Vehicles technology, the cloud control platform is used to detect the vehicle traffic operation status in real time and obtain vehicle operation status data;

[0041] S2: Based on vehicle operating status data and connected autonomous driving technology, when a traffic congestion is detected downstream via a cloud-based control platform, designated vehicles upstream of the congestion area are decelerated to a specified speed in advance, ensuring that the designated vehicles maintain a specified distance from the congested vehicles downstream.

[0042] S3: When the upstream designated vehicle is at a specified distance from the preceding vehicle, the cloud control platform is used to control the designated vehicle to accelerate back to its free flow speed before deceleration.

[0043] S4: Based on the driving behavior of the designated vehicle, the driving behaviors of the vehicles following the designated vehicle are adjusted accordingly according to the changes of the preceding vehicle;

[0044] S5: Based on the adjustment results, when the compression wave formed by the deceleration of the specified vehicle meets the dissipation wave formed by the acceleration during the upstream transmission process, the traffic congestion is eliminated, the vehicle maintains a constant free flow speed, and the elimination of expressway traffic congestion based on connected autonomous driving technology is completed.

[0045] In one embodiment of the present invention, Figure 2 The figure shows the system structure of an example of the present invention. That is, the vehicle networking technology is used to detect the operating status data of expressway vehicles and upload it to the cloud data management center. The data management center performs calculations and analysis and transmits the results to the cloud control platform. The cloud control platform formulates strategies and issues control instructions to vehicles in the expressway system. The specific implementation is as follows:

[0046] Traffic operation status detection: A vehicle network data management center is set up on the expressway. The connected autonomous driving vehicles on the expressway upload their position, speed, and headway distance to the data management center every 0.1s.

[0047] Traffic congestion generation and propagation: At time t1, a traffic congestion is detected at x meters in lane 1 and propagates steadily upstream along the lane. The speed of vehicles upstream of the congestion area is the free flow speed v f , the headway is h1; the speed of the vehicle stuck in congestion is 0, the headway is d; the speed of the vehicle that resumes driving after stopping in congestion is v f , the headway between the vehicles is h1.

[0048] Vehicle control parameter design and calculation: After detecting the formation and spread of congestion, design and calculate the corresponding parameters of the vehicle control method aimed at eliminating congestion, including:

[0049] The deceleration time of the designated upstream vehicle in S2 is the time when the congestion is detected after it is fully formed. The formula is:

[0050] t 减速 =t1

[0051] Among them, t 减速is the deceleration moment of the leading vehicle in the upstream of the congestion, and t1 is the moment when the congestion is detected after it is fully formed.

[0052] The designated vehicle upstream of S2 decelerates to the designated speed in advance. The formula is:

[0053]

[0054] Among them, v ai When the designated vehicle i is the deceleration head vehicle, its designated speed after deceleration is is the position where vehicle i-1 accelerates to leave the traffic jam after driving at the current free flow speed, d is the parking distance between adjacent vehicles, is the position of vehicle i at time t1, t i-1 The moment when vehicle i-1, traveling at the current free-flow speed, gets stuck in a traffic jam and then accelerates to leave.

[0055] The expected headway distance for the upstream designated vehicle in S2 to slow down to the designated speed in advance is:

[0056] h ai =v ai *t e

[0057] Among them, h ai is the expected headway distance corresponding to the decelerated speed, t e is the driver's desired headway. In S2, vehicle i is specified to meet the following conditions:

[0058]

[0059] Among them, Δt is the delay time of a single vehicle in congestion, When vehicle i is designated as the upstream leading vehicle to slow down in advance, the moment when the last decelerated vehicle returns to the free flow speed before deceleration is When vehicle i-1 is the leading vehicle in the upstream slowdown process, the moment when the last slowed vehicle returns to its free flow speed before deceleration. When vehicle i+1 is designated as the upstream leading vehicle to slow down in advance, the moment when the last decelerated vehicle returns to its pre-deceleration free flow speed;

[0060]

[0061] in, When vehicle i is designated as the deceleration head vehicle, it decelerates and then accelerates, T i is the time required for the dissipation wave generated by the acceleration of the designated vehicle i to catch up with the compression wave generated by its deceleration, l is the headway when the designated vehicle i returns to the free flow speed before deceleration, v f is the free flow speed of the vehicle, is the position where vehicle i accelerates, is the position where vehicle i decelerates, h1 is the headway between vehicles upstream in the congested area, and t 检测 is the time when the designated vehicle i decelerates, t0 is the time when the first vehicle in congestion starts to decelerate, x0 is the position where the first vehicle in congestion starts to decelerate, and x1 is the position where the first vehicle in congestion accelerates to return to free flow speed.

[0062] The headway distance when the vehicle accelerates and returns to the free flow speed before deceleration in S3 is:

[0063] l=v f *t e .

[0064] The time when the vehicle accelerates is specified in S3:

[0065]

[0066] From the above steps, it can be seen that each time a vehicle is tried as the head vehicle of the upstream deceleration vehicle in the congestion, the above control parameters corresponding to the vehicle as the head vehicle of the upstream deceleration vehicle in the congestion can be obtained, that is, the deceleration time t1 of the vehicle (the time when the congestion is detected), the position x at the time of deceleration, and the vehicle position x at the time of deceleration. i , the speed that the vehicle can maintain after decelerating as the lead vehicle Headroom h ai , acceleration time The moment when congestion is completely dissipated is T i .

[0067] Based on this, we tried and calculated the N+1 vehicles upstream of the congestion, and obtained the control parameters and effects of each vehicle as the leading vehicle in the upstream deceleration of the congestion, as shown in Table 1:

[0068] Table 1 Control parameters and results of selecting vehicle i as the deceleration head vehicle

[0069]

[0070] Select the leading vehicle in the upstream of the congestion to decelerate in advance: To eliminate traffic congestion as quickly as possible, the leading vehicle in the upstream of the congestion should enable the last vehicle participating in the deceleration to return to the free flow speed as soon as possible. That is, the moment when the compression wave caused by vehicle deceleration and acceleration meets the dissipation wave is also the moment when the congestion is completely eliminated. The leading vehicle i meets the following conditions:

[0071]

[0072] From Table 1 we can see that:

[0073]

[0074] Therefore, the Mth vehicle upstream of the congestion is selected as the first vehicle to slow down in advance.

[0075] Let the Mth vehicle upstream of the congestion slow down to v at time t1 am , the following vehicles follow accordingly, and the headway distance h am Keep moving.

[0076] Downstream congested vehicles at t m-1 All vehicles are restored to free flow speed at all times, leaving the congestion, and all congested vehicles are eliminated.

[0077] Let the Mth vehicle upstream of the congestion be At this moment, acceleration begins to reach the free flow velocity v f , the other decelerating vehicles behind the vehicle accelerate one by one to the free flow speed v f and with a headway spacing of 1.1v f Keep moving.

[0078] The last decelerated vehicle upstream of the congestion returns to its free flow speed v f , the congestion is completely eliminated. Subsequent vehicles are no longer affected by the congestion and maintain a stable free flow speed. Figure 3 As shown, the motion wave is completely eliminated. Each line in the figure represents the space-time trajectory of each vehicle, that is, the corresponding position of the vehicle at each moment, and the color represents the speed of the vehicle, that is, the slope of the line.

[0079] The present invention can detect and obtain the operating status of vehicles and traffic flows with high precision through vehicle network technology, and can control vehicle driving behavior and traffic operating status with high precision through automatic driving technology; by controlling the driving behavior of individual vehicles upstream of the congestion, the operating status of traffic flows upstream and downstream of the congestion can be coordinated, thereby completely eliminating the congestion. Compared with traditional manual coordination and control methods of the placement of restrictive facilities (speed limit boards, traffic lights, etc.), the present invention can completely eliminate traffic congestion in real time, greatly save the cost of congestion control, and significantly improve the initiative, flexibility, accuracy and efficiency of congestion elimination.

[0080] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and it should be understood that the scope of protection of the present invention is not limited to such specific descriptions and embodiments. Those skilled in the art can make various other specific variations and combinations based on the technical teachings disclosed in the present invention without departing from the essence of the present invention, and such variations and combinations are still within the scope of protection of the invention.

Claims

1. A method for eliminating traffic congestion on expressways based on connected autonomous driving technology, characterized in that: The following steps are involved: S1: Based on the Internet of Vehicles technology, the cloud control platform is used to detect the vehicle traffic operation status in real time and obtain vehicle operation status data; S2: Based on vehicle operating status data and connected autonomous driving technology, when a traffic congestion is detected downstream via a cloud-based control platform, designated vehicles upstream of the congestion area are decelerated to a specified speed in advance, ensuring that the designated vehicles maintain a specified distance from the congested vehicles downstream. The vehicle specified in S2 The following conditions are met: in, The delay time for a single vehicle stuck in congestion, For designated vehicles When the last decelerating vehicle returns to its free flow speed before deceleration, For vehicles When the last decelerating vehicle returns to its free flow speed before deceleration, For designated vehicles When serving as the leading vehicle in the upstream slowdown process, the moment when the last slowing vehicle returns to its pre-deceleration free flow speed; in, For designated vehicles When it is a deceleration vehicle, the moment it decelerates and then accelerates, For designated vehicles The time required for the evanescent wave produced by the acceleration to catch up with the compression wave produced by the deceleration, For designated vehicles The headway when returning to the free flow speed before deceleration, is the free flow speed of the vehicle, For designated vehicles The position of acceleration, For designated vehicles The position of deceleration, is the headway between vehicles upstream in the congested area, For designated vehicles The moment of slowing down, is the moment when congestion is detected after it is fully formed, The moment the first vehicle caught in the traffic jam begins to slow down, The position where the first vehicle caught in the congestion begins to slow down. The first vehicle stuck in the congestion is accelerated back to the free flow speed position, For designated vehicles For a deceleration head vehicle, the specified speed after deceleration is is the expected headway corresponding to the speed after deceleration; S3: When the upstream designated vehicle is at a specified distance from the preceding vehicle, the cloud control platform is used to control the designated vehicle to accelerate back to its free flow speed before deceleration. S4: Based on the driving behavior of the designated vehicle, the driving behaviors of the vehicles following the designated vehicle are adjusted accordingly according to the changes of the preceding vehicle; S5: Based on the adjustment results, when the compression wave formed by the deceleration of the specified vehicle meets the dissipation wave formed by the acceleration during the upstream transmission process, the traffic congestion is eliminated, the vehicle maintains a constant free flow speed, and the elimination of expressway traffic congestion based on connected autonomous driving technology is completed.

2. The method for eliminating traffic congestion on expressways based on connected autonomous driving technology according to claim 1, characterized in that: The deceleration time of the upstream designated vehicle in S2 is the time when the congestion is detected after it is fully formed, and the formula is: in, To reduce the speed of the leading vehicle in the upstream traffic jam in advance, The moment when congestion is detected after it is fully formed.

3. The method for eliminating traffic congestion on expressways based on connected autonomous driving technology according to claim 2, characterized in that: The upstream designated vehicle in S2 decelerates to the designated speed in advance, and the formula is: in, For designated vehicles For a deceleration head vehicle, the specified speed after deceleration is For vehicles At a location where you are accelerating out of a congestion after traveling at the current free-flow speed, is the parking distance between adjacent vehicles, For designated vehicles exist The location at the moment, For vehicles The moment when you accelerate out of a traffic jam after driving at the current free-flow speed.

4. The method for eliminating traffic congestion on expressways based on connected autonomous driving technology according to claim 3, characterized in that: The expected headway for the upstream designated vehicle in S2 to decelerate to the designated speed in advance is: in, is the expected headway distance corresponding to the decelerated speed, is the driver's desired headway.

5. The method for eliminating traffic congestion on expressways based on connected autonomous driving technology according to claim 4, characterized in that: The headway distance between vehicles when the vehicle accelerates and recovers to the free flow speed before deceleration in S3 is: 。 6. The method for eliminating traffic congestion on expressways based on connected autonomous driving technology according to claim 5, characterized in that: The time when the vehicle accelerates is specified in S3 as: 。

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